package cn.itcast.search.service.impl;

import cn.itcast.feign.client.ItemClient;
import cn.itcast.hmall.dto.common.PageDTO;
import cn.itcast.hmall.dto.common.ResultDTO;
import cn.itcast.hmall.dto.search.SearchReqDTO;
import cn.itcast.hmall.pojo.item.Item;
import cn.itcast.hmall.pojo.item.ItemDoc;
import cn.itcast.hmall.pojo.item.PageSelectItem;
import cn.itcast.search.service.SearchService;

import com.alibaba.fastjson.JSON;
import org.elasticsearch.action.bulk.BulkRequest;
import org.elasticsearch.action.delete.DeleteRequest;
import org.elasticsearch.action.index.IndexRequest;
import org.elasticsearch.action.search.SearchRequest;
import org.elasticsearch.action.search.SearchResponse;
import org.elasticsearch.client.RequestOptions;
import org.elasticsearch.client.RestHighLevelClient;
import org.elasticsearch.common.xcontent.XContentType;
import org.elasticsearch.index.query.BoolQueryBuilder;
import org.elasticsearch.index.query.QueryBuilders;
import org.elasticsearch.index.query.functionscore.FunctionScoreQueryBuilder;
import org.elasticsearch.index.query.functionscore.ScoreFunctionBuilders;
import org.elasticsearch.search.SearchHit;
import org.elasticsearch.search.SearchHits;
import org.elasticsearch.search.aggregations.AggregationBuilders;
import org.elasticsearch.search.aggregations.Aggregations;
import org.elasticsearch.search.aggregations.bucket.terms.Terms;
import org.elasticsearch.search.fetch.subphase.highlight.HighlightBuilder;
import org.elasticsearch.search.fetch.subphase.highlight.HighlightField;
import org.elasticsearch.search.sort.SortOrder;
import org.elasticsearch.search.suggest.Suggest;
import org.elasticsearch.search.suggest.SuggestBuilder;
import org.elasticsearch.search.suggest.SuggestBuilders;
import org.elasticsearch.search.suggest.completion.CompletionSuggestion;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.util.CollectionUtils;

import java.io.IOException;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;


@Service
public class SearchServiceImpl implements SearchService {
    @Autowired
    private RestHighLevelClient client;
    @Autowired
    private ItemClient itemClient;
    @Override
    public ResultDTO importSource() {
        try {
            PageSelectItem pageSelectItem = new PageSelectItem();
            Long page = 1L;
            Long size = 500L;
            pageSelectItem.setSize(size);
            pageSelectItem.setPage(page);
            PageDTO<Item> itemPageDTO = itemClient.pageSelect(pageSelectItem);
            int total = itemPageDTO.getTotal().intValue();
            for(;page*size<total+size;page++) {
                pageSelectItem.setPage(page);
                List<Item> lists = itemClient.pageSelect(pageSelectItem).getList();
                BulkRequest request = new BulkRequest();
                for (Item list : lists) {
                    ItemDoc itemDoc = new ItemDoc(list);
                    request.add(new IndexRequest("item")
                            .id(itemDoc.getId().toString())
                            .source(JSON.toJSONString(itemDoc), XContentType.JSON));
                }
                client.bulk(request, RequestOptions.DEFAULT);
            }

            return ResultDTO.ok();
        } catch (IOException e) {
            throw new RuntimeException("MYSQL导入Es异常");
        }
    }

    @Override
    public List<String> autoComplete(String param) {
        try {
            SearchRequest request = new SearchRequest("item");
            request.source().suggest(new SuggestBuilder().addSuggestion(
                    "mySuggestion",
                    SuggestBuilders.completionSuggestion("suggestion")
                            .prefix(param)
                            .skipDuplicates(true)
                            .size(10)
            ));
            SearchResponse response = client.search(request, RequestOptions.DEFAULT);
            ArrayList<String> list = new ArrayList<>();
            Suggest suggest = response.getSuggest();
            CompletionSuggestion suggestion = suggest.getSuggestion("mySuggestion");
            for (CompletionSuggestion.Entry.Option option : suggestion.getOptions()) {
                String text = option.getText().toString();
                list.add(text);
            }
            return list;
        } catch (IOException e) {
            throw new RuntimeException("补全失败");
        }
    }

    @Override
    public Map<String, List<String>> getFilters(SearchReqDTO params) {
        try {
            // 1.准备Request
            SearchRequest request = new SearchRequest("item");
            // 2.1.query
            buildBasicQuery(params, request);
            // 2.2.设置size
            request.source().size(0);
            // 2.3.聚合
            request.source().aggregation(AggregationBuilders
                    .terms("categoryAgg")
                    .field("category")
                    .size(10)
            );
            request.source().aggregation(AggregationBuilders
                    .terms("brandAgg")
                    .field("brand")
                    .size(10)
            );
            // 3.发出请求
            SearchResponse response = client.search(request, RequestOptions.DEFAULT);
            // 4.解析结果
            Map<String, List<String>> result = new HashMap<>();
            Aggregations aggregations = response.getAggregations();
            // 4.1.根据分类名称，获取分类结果
            List<String> categoryList = getAggByName(aggregations, "categoryAgg");
            result.put("category", categoryList);
            // 4.2.根据品牌名称，获取品牌结果
            List<String> brandList = getAggByName(aggregations, "brandAgg");
            result.put("brand", brandList);
            return result;
        } catch (IOException e) {
            throw new RuntimeException(e);
        }
    }

    @Override
    public PageDTO<ItemDoc> basicFind(SearchReqDTO params) {
        try {
            // 1.准备Request
            SearchRequest request = new SearchRequest("item");
            buildBasicQuery(params,request);
            //分页
            int start = params.getPage();
            int size = params.getSize();
            request.source().from((start - 1) * size).size(size);
            if(params.getSortBy().equals("sold")){
                request.source().sort(params.getSortBy(),SortOrder.DESC);
            }else if(params.getSortBy().equals("price")){
                request.source().sort(params.getSortBy(), SortOrder.ASC);
            }
            request.source().highlighter(new HighlightBuilder().field("name").requireFieldMatch(false));
            SearchResponse response = client.search(request, RequestOptions.DEFAULT);
            // 4.解析响应
            SearchHits searchHits = response.getHits();
            // 4.1.获取总条数
            long total = searchHits.getTotalHits().value;
            System.out.println("共搜索到" + total + "条数据");
            ArrayList<ItemDoc> list = new ArrayList<>();
            // 4.2.文档数组
            SearchHit[] hits = searchHits.getHits();
            // 4.3.遍历
            for (SearchHit hit : hits) {
                // 获取文档source
                String json = hit.getSourceAsString();
                // 反序列化
                ItemDoc itemDoc = JSON.parseObject(json, ItemDoc.class);
                Long price = (itemDoc.getPrice())*100;
                itemDoc.setPrice(price);
                list.add(itemDoc);
                // 获取高亮结果
                Map<String, HighlightField> highlightFields = hit.getHighlightFields();
                if (!CollectionUtils.isEmpty(highlightFields)) {
                    // 根据字段名获取高亮结果
                    HighlightField highlightField = highlightFields.get("name");
                    if (highlightField != null) {
                        // 获取高亮值
                        String name = highlightField.getFragments()[0].string();
                        // 覆盖非高亮结果
                        itemDoc.setName(name);
                    }
                }
            }
            return new PageDTO<>(total,list);
        } catch (IOException e) {
            throw new RuntimeException(e);
        }
    }

    @Override
    public void deleteById(Long id) {
        try {
            DeleteRequest request = new DeleteRequest("item", id.toString());
            client.delete(request, RequestOptions.DEFAULT);
            System.err.println("下架成功"+id);
        } catch (IOException e) {
            throw new RuntimeException(e);
        }
    }

    @Override
    public void insertById(Long id) {
        try {
            Item item = itemClient.selectOne(id.toString());
            ItemDoc itemDoc = new ItemDoc(item);
            IndexRequest request = new IndexRequest("item").id(item.getId().toString());
            request.source(JSON.toJSONString(itemDoc), XContentType.JSON);
            client.index(request, RequestOptions.DEFAULT);
            System.err.println("上架成功"+id);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    private List<String> getAggByName(Aggregations aggregations, String aggName) {
        // 4.1.根据聚合名称获取聚合结果
        Terms brandTerms = aggregations.get(aggName);
        // 4.2.获取buckets
        List<? extends Terms.Bucket> buckets = brandTerms.getBuckets();
        // 4.3.遍历
        List<String> brandList = new ArrayList<>();
        for (Terms.Bucket bucket : buckets) {
            // 4.4.获取key
            String key = bucket.getKeyAsString();
            brandList.add(key);
        }
        return brandList;
    }
    private void buildBasicQuery(SearchReqDTO params, SearchRequest request) {
        BoolQueryBuilder boolQuery = QueryBuilders.boolQuery();
        String key = params.getKey();
        if (key == null || "".equals(key)) {
            boolQuery.must(QueryBuilders.matchAllQuery());
        } else {
            boolQuery.must(QueryBuilders.matchQuery("all",key));
        }
        if(params.getCategory()!=null && !params.getCategory().equals("")){
            boolQuery.filter(QueryBuilders.termQuery("category",params.getCategory()));
        }
        if(params.getBrand()!=null && !params.getBrand().equals("")){
            boolQuery.filter(QueryBuilders.termQuery("brand",params.getBrand()));
        }
        if(params.getMinPrice()!=null && params.getMaxPrice()!=null){
            boolQuery.filter(QueryBuilders.rangeQuery("price").gte(params.getMinPrice()).lte(params.getMaxPrice()));
        }
        // 2.算分控制
        FunctionScoreQueryBuilder functionScoreQuery =
                QueryBuilders.functionScoreQuery(
                        // 原始查询，相关性算分的查询
                        boolQuery,
                        // function score的数组
                        new FunctionScoreQueryBuilder.FilterFunctionBuilder[]{
                                // 其中的一个function score 元素
                                new FunctionScoreQueryBuilder.FilterFunctionBuilder(
                                        // 过滤条件
                                        QueryBuilders.termQuery("isAD", true),
                                        // 算分函数
                                        ScoreFunctionBuilders.weightFactorFunction(10)
                                )
                        });
        request.source().query(functionScoreQuery);
    }
}
